[dm-devel] [PATCH v6 08/13] block: Add an explicit bio flag for bios that own their bvec

[Kent Overstreet]

On Wed, Aug 22, 2012 at 08:43:52PM +0300, Adrian Bunk wrote:
> On Wed, Aug 22, 2012 at 10:04:05AM -0700, Kent Overstreet wrote:
> >...
> > --- a/include/linux/blk_types.h
> > +++ b/include/linux/blk_types.h
> > @@ -117,6 +117,7 @@ struct bio {
> >   * BIO_POOL_IDX()
> >   */
> >  #define BIO_RESET_BITS	12
> > +#define BIO_OWNS_VEC	12	/* bio_free() should free bvec */
> >...
> 
> This doesn't look right.

Well, the first 12 bits are reset, so bit 12 will get preserved... I
guess it's unusual to have a duplicated enum value like that but
BIO_RESET_BITS is just a marker, not a real bit.